第9届表面工程国际会议 (ICSE 2024)

The surface of many biological organs exhibits unique micro/nano structures that can be used for the directional transport of droplets and spheres. It has important research value in microfluidic, biomedical analysis, chemical reaction and so on. However, achieving efficient dynamic manipulation of multiform matter in different media remains a major challenge.
In this study, magnetic response Fe₃O₄@PDMS@SiO₂ omniphobic (hydrophobic, oleophobic) microciliary arrays (MMAs) were prepared by combining laser direct writing technology with template method. Due to the modification of the hydrophobic SiO₂, the optimized MMAs has a water contact Angle greater than 140°, a rolling Angle less than 3°, and an oil contact Angle of 129°. Thus, when stimulated by a moving magnet, the microciliary columns bend and deform successively in a wavy fashion. This creates a directional driving force that quickly transports water droplets and solid balls. MMAs can dynamically control water droplets (up to 25μL), oil droplets, solid balls (up to 2g), water droplets and bubbles in the air medium; Continuous delivery at a maximum speed of 2.4mm/s. This multi-substance delivery strategy is expected to be applied to biomedical processes, targeted drug delivery, and microfluidic technologies.
 

Nanosecond laser processing, magnetically responsive microciliary arrays, fully hydrophobic, droplet manipulation